Performance and Feasibility of Therapeutic Vibrating Mesh Nebulizer for Ventilation Lung Scan

This study aimed to evaluate the performance of a therapeutic vibrating mesh-type nebulizer for the pulmonary delivery of radioaerosols for lung scintigraphy in healthy subjects. Six healthy subjects (mean age of 28.7 ± 6.2 y) inhaled 2 mL of Tc-99m diethylenetriaminepentaacetic acid (DTPA) and normal saline solution (20 mCi) via the therapeutic vibrating mesh nebulizer (DK010, DELBio, Taipei, Taiwan). The nebulizer’s mass median aerodynamic diameter (MMAD) is between 2.3 μm and 5.0 μm (3.47 ± 0.37 μm) and the nebulization rate is greater than 0.2 ml/min. Scintigraphy was performed to count radioaerosols in the regions of interest to determine the total and regional lung deposition and extrathoracic airway deposition of aerosols, penetration of aerosols, and radioactivity count balance. The total lung deposition of aerosols was 21.2 ± 5.2% (% ex-valve dose), 27.4 ± 8.0% (% ex-device dose) and 13.8 ± 4.1% (% initial dose) in nebulizer. The extrathoracic airway deposition was 4.8 ± 1.1%. The radioactivity count balance was 5.4 ± 3.0%. The ratio of outer vs inner lung deposition (O/I ratio, or penetration index) was 1.89 ± 0.55. The delivery efficiency and the penetration of aerosols to the peripheral lung achieved by the DELBio DK010 vibrating mesh-type nebulizer are similar to the commercialized jet-type nebulizers dedicated for radioaerosol lung scintigraphy nebulizer. The therapeutic vibrating mesh-type nebulizer (DELBio DK010) is feasible for radionuclide lung ventilation scintigraphy.

Current strategies for managing CTEPH: results of the worldwide prospective CTEPH Registry

BackgroundPulmonary endarterectomy (PEA), pulmonary arterial hypertension (PAH) therapy, and balloon pulmonary angioplasty (BPA) are currently accepted therapies for chronic thromboembolic pulmonary hypertension (CTEPH). This international CTEPH registry identifies clinical characteristics of patients, diagnostic algorithms, and treatment decisions in a global context.Methods1010 newly diagnosed consecutive patients were included into the registry between February 2015 and September 2016. Diagnosis was confirmed by right heart catheterisation, ventilation-perfusion lung scan, computerised pulmonary angiography, and/or invasive pulmonary angiography after at least 3 months on anticoagulation.ResultsOverall, 649 patients (64.3%) were considered for PEA, 193 (19.1%) for BPA, 20 (2.0%) for both PEA and BPA and 148 (14.7%) for PAH therapy only. Reasons for PEA inoperability: technical inaccessibility (n=235), co-morbidities (n=63), and patient refusal (n=44). In Europe, America and other countries (AAO), 72% of patients were deemed suitable for PEA whereas in Japan, 70% of patients were offered BPA as first choice. Gender was evenly balanced, except in Japan where 75% of patients were female. A history of acute pulmonary embolism was reported for 65.6% of patients. At least one PAH therapy was initiated in 35.8% of patients (26.2% of PEA candidates, 54.5% of BPA candidates, and 54.1% of those not eligible for either PEA or BPA). At the time of analysis, 39 patients (3.9%) had died of PH-related causes (3.5% after PEA and 1.8% after BPA).ConclusionsThe registry revealed noticeable differences in patient characteristics (rates of pulmonary embolism and gender) and therapeutic approaches in Japan compared with Europe and AAO.

AI-Empowered Computational Examination of Chest Imaging for COVID-19 Treatment: A Review

Since the first case of coronavirus disease 2019 (COVID-19) was discovered in December 2019, COVID-19 swiftly spread over the world. By the end of March 2021, more than 136 million patients have been infected. Since the second and third waves of the COVID-19 outbreak are in full swing, investigating effective and timely solutions for patients’ check-ups and treatment is important. Although the SARS-CoV-2 virus-specific reverse transcription polymerase chain reaction test is recommended for the diagnosis of COVID-19, the test results are prone to be false negative in the early course of COVID-19 infection. To enhance the screening efficiency and accessibility, chest images captured via X-ray or computed tomography (CT) provide valuable information when evaluating patients with suspected COVID-19 infection. With advanced artificial intelligence (AI) techniques, AI-driven models training with lung scans emerge as quick diagnostic and screening tools for detecting COVID-19 infection in patients. In this article, we provide a comprehensive review of state-of-the-art AI-empowered methods for computational examination of COVID-19 patients with lung scans. In this regard, we searched for papers and preprints on bioRxiv, medRxiv, and arXiv published for the period from January 1, 2020, to March 31, 2021, using the keywords of COVID, lung scans, and AI. After the quality screening, 96 studies are included in this review. The reviewed studies were grouped into three categories based on their target application scenarios: automatic detection of coronavirus disease, infection segmentation, and severity assessment and prognosis prediction. The latest AI solutions to process and analyze chest images for COVID-19 treatment and their advantages and limitations are presented. In addition to reviewing the rapidly developing techniques, we also summarize publicly accessible lung scan image sets. The article ends with discussions of the challenges in current research and potential directions in designing effective computational solutions to fight against the COVID-19 pandemic in the future.

Laboratory and demographic findings among patients with coronavirus disease 2019: A review

Coronavirus disease 2019 (COVID-19) is the third known animal coronavirus, after severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome coronavirus (MERS-CoV). The mean age of the infected patients was estimated to be between 50 and 69 years old. Accordingly, the COVID-19 mortality rate was calculated as 15%. In this regard, the essential component of prevention and planning is knowledge of laboratory and demographic findings among COVID-19 patients; therefore, the present study was conducted to investigate laboratory and demographic findings among these patients worldwide. This systematic review was performed on the articles published in English between January 1, 2019 and May 4, 2020, using MeSH-compliant keywords such as "COVID-19", "Laboratory, coronavirus disease-19 testing", and " demography " in international databases (PubMed, and web of science Scopus). Thereafter, the articles relevant to laboratory and demographic findings among COVID-19 patients were included in the final review. Reviewing the included articles showed changes in the mean lymphocytes count ranged from 0.7 to 39 in hospital or severe cases. Moreover, Leukopenia was not observed in patients with thrombocytopenia. In addition, C-reactive protein (CRP), leukocytes, D-dimer, FDP, FIB, neutrophils, AST, serum creatinine, t-troponin, troponin I, and blood bilirubin levels showed increasing trends in most studies conducted on COVID-19 patients. Notably, the elevated LDH level was more common among children than adults. According to the results of the present study, and by considering the clinical characteristics of COVID-19 patients on the one hand, and considering the changes in laboratory samples such as lymphocytes and other blood markers due to the damaged myocardial, hepatic, and renal tissues on the other hand, it is recommended to confirm the diagnosis of this infection by evaluating the patients’ blood samples using other diagnostic methods like lung scan.

A giant isolated right coronary aneurism

A previously healthy 32-year-old female hailing from Mexico presented to the emergency department with rectorrhagia. Caseating granulomas were detected on histopathological analysis from cecum ulcerative lesions. A purified protein derivative skin test resulted positive. In order to exclude pulmonary tubercolosis a CT lung scan was performed: a rounded and voluminous mass, located above the right atrioventricular cardiac junction, was unexpectedly revealed. Further a cardiac magnetic resonance and a coronary angiography disclosed a giant (5 × 4,8 cm) isolated aneurysm of proximal right coronary artery with severe thrombotic layering. The patient was treated with isoniazid, rifampin, ethambutol, and pyrazinamide; after approximately 2 months of treatment she had complete resolution of cecal lesions. Anticoagulant oral therapy with warfarin was started and the patient was submitted to CABG.

Clinical validation of time reduction strategy in continuous step-and-shoot mode during SPECT acquisition

Background The SwiftScan solution (General Electric Healthcare) combines a new low-energy high-resolution sensitivity collimator and a tomographic step-and-shoot continuous (SSC) mode acquisition. The purpose of this study is to determine whether SSC mode can be used in clinical practice with shorter examination times, while preserving image quality and ensuring accurate semi-quantification. Twenty bone scan and 10 lung scan studies were randomly selected over a period of 2 months. Three sets of image datasets were produced: step-and-shoot (SS) acquisition, simulated 25% count reduction using the Poisson resampling method (SimSS), and SimSS continuous acquisition (SimSSC), where SimSS was summed with counts acquired during detector head rotation. Visual assessment (5-point Likert scale, 2 readers) and semi-quantitative evaluation (50 focal uptake from 10 bone studies), assessed by SUVmean, coefficient of variation (COV), and contrast-to-noise ratio (CNR), were performed using t test and Bland-Altman analysis. Results Intra-reader agreement was substantial for reader 1 (k = 0.71) and for reader 2 (k = 0.61). Inter-reader agreement was substantial for SS set (k = 0.93) and moderate for SimSSC (k = 0.52). Bland-Altman analysis showed a good interchangeability of SS and SimSSC SUV values. The mean CNR between SS and SimSSC was not significantly different: 42.9 ± 43.7 [23.7–62.1] vs. 43.1 ± 46 [22.9–63.3] (p = 0.46), respectively. COV values, assessing noise level, did not deviate significantly between SS and SimSSC: 0.20 ± 0.08 [0.18–0.23] vs. 0.21 ± 0.08, [0.18–0.23] (p = 0.15), respectively, whereas a significant difference was demonstrated between SS and SimSS: 0.20 ± 0.08 [0.18–0.23] vs. 0.23 ± 0.09 [0.20–0.25] (p < 0.0001), respectively. Conclusions SSC mode acquisition decreases examination time by approximately 25% in bone and lung SPECT/CT studies compared to SS mode (~ 2 min per single-bed SPECT), without compromising image quality and signal quantification. This SPECT sensitivity improvement also offers the prospect of more comfortable exams, with less motion artifacts, especially in painful or dyspneic patients.

The Impact of Pulmonary Vascular Obstruction on the Risk of Recurrence of Pulmonary Embolism: A French Prospective Cohort

Background We aimed to assess whether high pulmonary vascular obstruction index (PVOI) measured at the time of pulmonary embolism (PE) diagnosis is associated with an increased risk of recurrent venous thromboembolism (VTE). Study Design and Methods French prospective cohort of patients with a symptomatic episode of PE diagnosed with spiral computerized tomography pulmonary angiography (CTPA) or ventilation-perfusion (V/Q) lung scan and a follow-up of at least 6 months after anticoagulation discontinuation. PVOI was assessed based on the available diagnostic exam (V/Q lung scan or CTPA). All patients had standardized follow-up and independent clinicians adjudicated all deaths and recurrent VTE events. Main outcome was recurrent VTE after stopping anticoagulation. Results A total of 418 patients with PE were included. During a median follow-up period of 3.6 (1.2–6.0) years, 109 recurrences occurred. In multivariate analysis, PVOI ≥ 40% was an independent risk factor for recurrence (hazard ratio 1.77, 95% confidence interval 1.20–2.62, p < 0.01), whether PE was provoked by a major transient risk factor or not. A threshold at 41% was identified as the best value associated with the risk of recurrence 6 months after stopping anticoagulation (area under curve = 0.64). Conclusion PVOI ≥ 40% at PE diagnosis was an independent risk factor for recurrence VTE. Further prospective validation studies are needed.

Risk of Acute Kidney Injury after Intravenous Contrast Media Administration in Patients with Suspected Pulmonary Embolism: A Propensity-Matched Study

Background Although computed tomography pulmonary angiography (CTPA) is the preferred diagnostic procedure in patients with suspected pulmonary embolism (PE), some patients undergo ventilation/perfusion (V/Q) lung scan due to concern of contrast-associated acute kidney injury (AKI). Methods The study used a cohort of 4,565 patients with suspected PE. Patients who received contrast during CTPA were compared with propensity score-matched unexposed control patients who underwent V/Q lung scanning. AKI was defined as ≥50% increase in serum creatinine during the first 72 hours after either CTPA or V/Q lung scan. Results Classification and regression tree analysis demonstrated that baseline creatinine was the strongest determinant of the decision to use CTPA. Propensity-score matching yielded 969 patient pairs. There were 44 AKI events (4.5%) in patients exposed to contrast media (CM) and 33 events (3.4%) in patients not exposed to CM (risk difference: 1.1%, 95% confidence interval [CI]: −0.6 to 2.9%; odds ratio [OR]: 1.39, 95% CI: 0.86–2.26; p = 0.18). Using different definitions for AKI and extending the time window for AKI diagnosis gave similar results. In a sensitivity analysis with the inverse probability weighting method, the OR for AKI in the CTPA versus V/Q scan was 1.14 (95% CI: 0.72–1.78; p = 0.58). Conclusion Intravenous contrast material administration was not associated with an increased risk of AKI in patients with suspected PE. Given the diagnostic superiority of CTPA, these results are reassuring with regard to the use of CTPE in patients with suspected PE perceived to be at risk for AKI.

Hypersensitivity pneumonitis complicated by acute respiratory viral infection

The article presents a clinical case of hypersensitivity pneumonitis complicated by a viral infection in a 72-year-old woman. The introductory part provides a concise literature review on the etiology, classification, frequency, and possible complications of hypersensitivity pneumonitis. The patient’s computed tomography (CT) lung scan showed bilateral interstitial lesions. The patient was diagnosed with idiopathic pulmonary fibrosis based on the clinical manifestations and radiological findings. The autopsy revealed morphological signs of hypersensitivity pneumonitis (obliterative bronchiolitis, moderate interstitial fibrosis with honey-combing, nonspecific interstitial pneumonia, giant multinucleated cells) and viral lung damage (exudative stage of acute respiratory distress syndrome with interalveolar edema, hyaline membranes lining the alveoli, pneumocyte desquamation, and ugly giant cells). Keywords: hypersensitivity pneumonitis, exogenous allergic alveolitis, viral infection, lungs

Outcome at 26 Years After Repair of Fallot’s Tetralogy With Absent Left Pulmonary Artery

We report long-term outcome after two-stage, “one lung repair” in a four-year-old boy with tetralogy of Fallot and congenital absence of the left pulmonary artery. The operation was carried out two years after a palliative aortopulmonary central shunt and was uneventful. Twenty-six years later, the patient is in excellent clinical condition, with normal peripheral oxygen saturation. A recent radionuclide lung scan and cardiac magnetic resonance imaging show the pulmonary flow entirely directed into the right lung. In selected cases, the long-term prognosis of patients with tetralogy of Fallot and true absence of left pulmonary artery after “one lung repair” may be excellent.